The Venom Gland Transcriptome of Tityus paraguayensis Reveals a Diverse Array of Bioactive Molecules from the Brazilian Cerrado

Introduction: Scorpions are arthropods whose metasoma ends in a telson containing venom glands. Their venom is a bioactive mix of proteins and peptides that supports predation and defense and may have antimicrobial, ion-channel-modulating, antitumor, coagulation, and homeostatic effects. Transcriptomics offers a cost-effective way to characterize venom by capturing all transcripts in the glands. Objective: This study aimed to obtain and to examine the transcriptomic profile of the venom glands of Tityus paraguayensis, a scorpion endemic to the Brazilian Cerrado. Methodology: After collecting T. paraguayensis specimens, we extracted total RNA from the venom glands and quantified  it using a NanoDrop ND -1000 spectrophotometer. A cDNA library was constructed, and sequencing was performed using an Illumina® NextSeq 550 platform. In silico analyses were conducted to assemble  transcripts and provide  functional annotations of the genes expressed in the venom glands. Results: De novo assembly identified 37,283 transcripts and 29,304 genes, with a GC content of 35.69% and a mean transcript length of 787.9 bp. Of the 37,283 assembled transcripts, 64.34% were annotated; of  these, 62.94% were classified as constitutive components of the glandular tissue, and 1.4% as potential components of the venom. Venom-related transcripts include peptides that modulate sodium (8%), potassium (9%), and calcium (1%) channels, antimicrobial peptides (6%), antihypertensives (2%), phospholipases (1%), and metalloproteinases (29%), along with other compounds (44%). Specific highlights include the structural-functional analysis of four key peptides: TpNa3, a probable β-toxin sodium channel modulator with a βαββ structural motif; TpHyp1, a long-chain antihypertensive peptide containing the conserved KPP motif; TpAP1, a short antimicrobial peptide with low positive charge and an α-helical structure; and TpK8, a potassium toxin previously partially identified (α-KTx). Conclusion: These results highlight the broad diversity of compounds present in the venom of T. paraguayensis, underscoring its potential for pharmacological applications.